Add trap handlers for protected VMs. These are mainly for Sys64 and debug traps.
No functional change intended as these are not hooked in yet. Signed-off-by: Fuad Tabba <[email protected]> --- arch/arm64/include/asm/kvm_hyp.h | 3 + arch/arm64/kvm/arm.c | 3 + arch/arm64/kvm/hyp/nvhe/Makefile | 2 +- arch/arm64/kvm/hyp/nvhe/sys_regs.c | 475 +++++++++++++++++++++++++++++ 4 files changed, 482 insertions(+), 1 deletion(-) create mode 100644 arch/arm64/kvm/hyp/nvhe/sys_regs.c diff --git a/arch/arm64/include/asm/kvm_hyp.h b/arch/arm64/include/asm/kvm_hyp.h index 9d60b3006efc..7e81e42107e1 100644 --- a/arch/arm64/include/asm/kvm_hyp.h +++ b/arch/arm64/include/asm/kvm_hyp.h @@ -115,7 +115,10 @@ int __pkvm_init(phys_addr_t phys, unsigned long size, unsigned long nr_cpus, void __noreturn __host_enter(struct kvm_cpu_context *host_ctxt); #endif +extern u64 kvm_nvhe_sym(id_aa64pfr0_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64pfr1_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val); extern u64 kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val); +extern u64 kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val); #endif /* __ARM64_KVM_HYP_H__ */ diff --git a/arch/arm64/kvm/arm.c b/arch/arm64/kvm/arm.c index d71da6089822..363493395eba 100644 --- a/arch/arm64/kvm/arm.c +++ b/arch/arm64/kvm/arm.c @@ -1751,8 +1751,11 @@ static int kvm_hyp_init_protection(u32 hyp_va_bits) void *addr = phys_to_virt(hyp_mem_base); int ret; + kvm_nvhe_sym(id_aa64pfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR0_EL1); + kvm_nvhe_sym(id_aa64pfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64PFR1_EL1); kvm_nvhe_sym(id_aa64mmfr0_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR0_EL1); kvm_nvhe_sym(id_aa64mmfr1_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR1_EL1); + kvm_nvhe_sym(id_aa64mmfr2_el1_sys_val) = read_sanitised_ftr_reg(SYS_ID_AA64MMFR2_EL1); ret = create_hyp_mappings(addr, addr + hyp_mem_size, PAGE_HYP); if (ret) diff --git a/arch/arm64/kvm/hyp/nvhe/Makefile b/arch/arm64/kvm/hyp/nvhe/Makefile index 5df6193fc430..a23f417a0c20 100644 --- a/arch/arm64/kvm/hyp/nvhe/Makefile +++ b/arch/arm64/kvm/hyp/nvhe/Makefile @@ -14,7 +14,7 @@ lib-objs := $(addprefix ../../../lib/, $(lib-objs)) obj-y := timer-sr.o sysreg-sr.o debug-sr.o switch.o tlb.o hyp-init.o host.o \ hyp-main.o hyp-smp.o psci-relay.o early_alloc.o stub.o page_alloc.o \ - cache.o setup.o mm.o mem_protect.o + cache.o setup.o mm.o mem_protect.o sys_regs.o obj-y += ../vgic-v3-sr.o ../aarch32.o ../vgic-v2-cpuif-proxy.o ../entry.o \ ../fpsimd.o ../hyp-entry.o ../exception.o ../pgtable.o obj-y += $(lib-objs) diff --git a/arch/arm64/kvm/hyp/nvhe/sys_regs.c b/arch/arm64/kvm/hyp/nvhe/sys_regs.c new file mode 100644 index 000000000000..ab09ccc64fea --- /dev/null +++ b/arch/arm64/kvm/hyp/nvhe/sys_regs.c @@ -0,0 +1,475 @@ +// SPDX-License-Identifier: GPL-2.0-only +/* + * Copyright (C) 2021 Google LLC + * Author: Fuad Tabba <[email protected]> + */ + +#include <linux/kvm_host.h> + +#include <asm/kvm_asm.h> +#include <asm/kvm_emulate.h> +#include <asm/kvm_mmu.h> + +#include <hyp/adjust_pc.h> + +#include "../../sys_regs.h" + +/* + * Copies of the host's CPU features registers holding sanitized values. + */ +u64 id_aa64pfr0_el1_sys_val; +u64 id_aa64pfr1_el1_sys_val; +u64 id_aa64mmfr2_el1_sys_val; + +/* + * Inject an undefined exception to the guest. + */ +static void inject_undef(struct kvm_vcpu *vcpu) +{ + u32 esr = (ESR_ELx_EC_UNKNOWN << ESR_ELx_EC_SHIFT); + + vcpu->arch.flags |= (KVM_ARM64_EXCEPT_AA64_EL1 | + KVM_ARM64_EXCEPT_AA64_ELx_SYNC | + KVM_ARM64_PENDING_EXCEPTION); + + __kvm_adjust_pc(vcpu); + + write_sysreg_el1(esr, SYS_ESR); + write_sysreg_el1(read_sysreg_el2(SYS_ELR), SYS_ELR); + write_sysreg_el2(*vcpu_pc(vcpu), SYS_ELR); + write_sysreg_el2(*vcpu_cpsr(vcpu), SYS_SPSR); +} + +/* + * Accessor for undefined accesses. + */ +static bool undef_access(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + inject_undef(vcpu); + return false; +} + +/* + * Accessors for feature registers. + * + * If access is allowed, set the regval to the protected VM's view of the + * register and return true. + * Otherwise, inject an undefined exception and return false. + */ + +/* Accessor for ID_AA64PFR0_EL1. */ +static bool pvm_access_id_aa64pfr0(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + const struct kvm *kvm = (const struct kvm *) kern_hyp_va(vcpu->kvm); + u64 allow_mask = 0; + u64 set_mask = 0; + + if (p->is_write) + return undef_access(vcpu, p, r); + + /* + * Only allow: + * - Floating-point + * - Advanced SIMD + * - Data Independent Timing + */ + allow_mask |= FEATURE(ID_AA64PFR0_FP) | + FEATURE(ID_AA64PFR0_ASIMD) | + FEATURE(ID_AA64PFR0_DIT); + + /* - ARMv8.4-RAS (not later than v1) */ + if (id_aa64pfr0_el1_sys_val & FEATURE(ID_AA64PFR0_RAS)) + set_mask |= FIELD_PREP(FEATURE(ID_AA64PFR0_RAS), + ID_AA64PFR0_RAS_V1); + + /* - AArch64 guests */ + set_mask |= FIELD_PREP(FEATURE(ID_AA64PFR0_EL0), + ID_AA64PFR0_EL0_64BIT_ONLY) | + FIELD_PREP(FEATURE(ID_AA64PFR0_EL1), + ID_AA64PFR0_EL1_64BIT_ONLY) | + FIELD_PREP(FEATURE(ID_AA64PFR0_EL2), + ID_AA64PFR0_EL2_64BIT_ONLY); + + /* (only set EL3 exception handling if EL3 exists) */ + if (id_aa64pfr0_el1_sys_val & FEATURE(ID_AA64PFR0_EL3)) + set_mask |= FIELD_PREP(FEATURE(ID_AA64PFR0_EL3), + ID_AA64PFR0_EL3_64BIT_ONLY); + + /* - Spectre and Meltdown mitigation */ + set_mask |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV2), + (u64)kvm->arch.pfr0_csv2); + set_mask |= FIELD_PREP(FEATURE(ID_AA64PFR0_CSV3), + (u64)kvm->arch.pfr0_csv3); + + p->regval = (id_aa64pfr0_el1_sys_val & allow_mask) | set_mask; + return true; +} + +/* Accessor for ID_AA64PFR1_EL1. */ +static bool pvm_access_id_aa64pfr1(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 allow_mask = 0; + + if (p->is_write) + return undef_access(vcpu, p, r); + + /* + * Only allow: + * - Branch Target Identification + * - Speculative Store Bypassing + */ + allow_mask |= FEATURE(ID_AA64PFR1_BT) | + FEATURE(ID_AA64PFR1_SSBS); + + p->regval = id_aa64pfr1_el1_sys_val & allow_mask; + return true; +} + +/* Accessor for ID_AA64ZFR0_EL1. */ +static bool pvm_access_id_aa64zfr0(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return undef_access(vcpu, p, r); + + /* No support for Scalable Vectors */ + p->regval = 0; + return true; +} + +/* Accessor for ID_AA64DFR0_EL1. */ +static bool pvm_access_id_aa64dfr0(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return undef_access(vcpu, p, r); + + /* No support for debug, including breakpoints, and watchpoints */ + p->regval = 0; + return true; +} + +/* Accessor for ID_AA64MMFR0_EL1. */ +static bool pvm_access_id_aa64mmfr0(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 allow_mask = 0; + u64 set_mask = 0; + + if (p->is_write) + return undef_access(vcpu, p, r); + + /* + * Only allow: + * - Mixed-endian + * - Distinction between Secure and Non-secure Memory + * - Mixed-endian at EL0 only + * - Non-context synchronizing exception entry and exit + */ + allow_mask |= FEATURE(ID_AA64MMFR0_BIGENDEL) | + FEATURE(ID_AA64MMFR0_SNSMEM) | + FEATURE(ID_AA64MMFR0_BIGENDEL0) | + FEATURE(ID_AA64MMFR0_EXS); + + /* + * - 40-bit IPA + * - 16-bit ASID + * - 4KB granule + */ + set_mask |= FIELD_PREP(FEATURE(ID_AA64MMFR0_PARANGE), + ID_AA64MMFR0_PARANGE_40) | + FIELD_PREP(FEATURE(ID_AA64MMFR0_ASID), + ID_AA64MMFR0_ASID_16) | + FIELD_PREP(FEATURE(ID_AA64MMFR0_TGRAN64), + ID_AA64MMFR0_TGRAN64_NI); + + p->regval = (id_aa64mmfr0_el1_sys_val & allow_mask) | set_mask; + return true; +} + +/* Accessor for ID_AA64MMFR1_EL1. */ +static bool pvm_access_id_aa64mmfr1(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 allow_mask = 0; + + if (p->is_write) + return undef_access(vcpu, p, r); + + /* + * Only allow: + * - Hardware translation table updates to Access flag and Dirty state + * - Number of VMID bits from CPU + * - Hierarchical Permission Disables + * - Privileged Access Never + * - SError interrupt exceptions from speculative reads + * - Enhanced Translation Synchronization + */ + allow_mask |= FEATURE(ID_AA64MMFR1_HADBS) | + FEATURE(ID_AA64MMFR1_VMIDBITS) | + FEATURE(ID_AA64MMFR1_HPD) | + FEATURE(ID_AA64MMFR1_PAN) | + FEATURE(ID_AA64MMFR1_SPECSEI) | + FEATURE(ID_AA64MMFR1_ETS); + + p->regval = id_aa64mmfr1_el1_sys_val & allow_mask; + return true; +} + +/* Accessor for ID_AA64MMFR2_EL1. */ +static bool pvm_access_id_aa64mmfr2(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + u64 allow_mask = 0; + + if (p->is_write) + return undef_access(vcpu, p, r); + + /* + * Only allow: + * - Common not Private translations + * - User Access Override + * - IESB bit in the SCTLR_ELx registers + * - Unaligned single-copy atomicity and atomic functions + * - ESR_ELx.EC value on an exception by read access to feature ID space + * - TTL field in address operations. + * - Break-before-make sequences when changing translation block size + * - E0PDx mechanism + */ + allow_mask |= FEATURE(ID_AA64MMFR2_CNP) | + FEATURE(ID_AA64MMFR2_UAO) | + FEATURE(ID_AA64MMFR2_IESB) | + FEATURE(ID_AA64MMFR2_AT) | + FEATURE(ID_AA64MMFR2_IDS) | + FEATURE(ID_AA64MMFR2_TTL) | + FEATURE(ID_AA64MMFR2_BBM) | + FEATURE(ID_AA64MMFR2_E0PD); + + p->regval = id_aa64mmfr2_el1_sys_val & allow_mask; + return true; +} + +/* + * Accessor for AArch32 Processor Feature Registers. + * + * The value of these registers is "unknown" according to the spec if AArch32 + * isn't supported. + */ +static bool pvm_access_id_aarch32(struct kvm_vcpu *vcpu, + struct sys_reg_params *p, + const struct sys_reg_desc *r) +{ + if (p->is_write) + return undef_access(vcpu, p, r); + + /* Use 0 for architecturally "unknown" values. */ + p->regval = 0; + return true; +} + +/* Mark the specified system register as an AArch32 feature register. */ +#define AARCH32(REG) { SYS_DESC(REG), .access = pvm_access_id_aarch32 } + +/* Mark the specified system register as not being handled in hyp. */ +#define HOST_HANDLED(REG) { SYS_DESC(REG), .access = NULL } + +/* + * Architected system registers. + * Important: Must be sorted ascending by Op0, Op1, CRn, CRm, Op2 + * + * NOTE: Anything not explicitly listed here will be *restricted by default*, + * i.e., it will lead to injecting an exception into the guest. + */ +static const struct sys_reg_desc pvm_sys_reg_descs[] = { + /* Cache maintenance by set/way operations are restricted. */ + + /* Debug and Trace Registers are all restricted */ + + /* AArch64 mappings of the AArch32 ID registers */ + /* CRm=1 */ + AARCH32(SYS_ID_PFR0_EL1), + AARCH32(SYS_ID_PFR1_EL1), + AARCH32(SYS_ID_DFR0_EL1), + AARCH32(SYS_ID_AFR0_EL1), + AARCH32(SYS_ID_MMFR0_EL1), + AARCH32(SYS_ID_MMFR1_EL1), + AARCH32(SYS_ID_MMFR2_EL1), + AARCH32(SYS_ID_MMFR3_EL1), + + /* CRm=2 */ + AARCH32(SYS_ID_ISAR0_EL1), + AARCH32(SYS_ID_ISAR1_EL1), + AARCH32(SYS_ID_ISAR2_EL1), + AARCH32(SYS_ID_ISAR3_EL1), + AARCH32(SYS_ID_ISAR4_EL1), + AARCH32(SYS_ID_ISAR5_EL1), + AARCH32(SYS_ID_MMFR4_EL1), + AARCH32(SYS_ID_ISAR6_EL1), + + /* CRm=3 */ + AARCH32(SYS_MVFR0_EL1), + AARCH32(SYS_MVFR1_EL1), + AARCH32(SYS_MVFR2_EL1), + AARCH32(SYS_ID_PFR2_EL1), + AARCH32(SYS_ID_DFR1_EL1), + AARCH32(SYS_ID_MMFR5_EL1), + + /* AArch64 ID registers */ + /* CRm=4 */ + { SYS_DESC(SYS_ID_AA64PFR0_EL1), .access = pvm_access_id_aa64pfr0 }, + { SYS_DESC(SYS_ID_AA64PFR1_EL1), .access = pvm_access_id_aa64pfr1 }, + { SYS_DESC(SYS_ID_AA64ZFR0_EL1), .access = pvm_access_id_aa64zfr0 }, + { SYS_DESC(SYS_ID_AA64DFR0_EL1), .access = pvm_access_id_aa64dfr0 }, + HOST_HANDLED(SYS_ID_AA64DFR1_EL1), + HOST_HANDLED(SYS_ID_AA64AFR0_EL1), + HOST_HANDLED(SYS_ID_AA64AFR1_EL1), + HOST_HANDLED(SYS_ID_AA64ISAR0_EL1), + HOST_HANDLED(SYS_ID_AA64ISAR1_EL1), + { SYS_DESC(SYS_ID_AA64MMFR0_EL1), .access = pvm_access_id_aa64mmfr0 }, + { SYS_DESC(SYS_ID_AA64MMFR1_EL1), .access = pvm_access_id_aa64mmfr1 }, + { SYS_DESC(SYS_ID_AA64MMFR2_EL1), .access = pvm_access_id_aa64mmfr2 }, + + HOST_HANDLED(SYS_SCTLR_EL1), + HOST_HANDLED(SYS_ACTLR_EL1), + HOST_HANDLED(SYS_CPACR_EL1), + + HOST_HANDLED(SYS_RGSR_EL1), + HOST_HANDLED(SYS_GCR_EL1), + + /* Scalable Vector Registers are restricted. */ + + HOST_HANDLED(SYS_TTBR0_EL1), + HOST_HANDLED(SYS_TTBR1_EL1), + HOST_HANDLED(SYS_TCR_EL1), + + HOST_HANDLED(SYS_APIAKEYLO_EL1), + HOST_HANDLED(SYS_APIAKEYHI_EL1), + HOST_HANDLED(SYS_APIBKEYLO_EL1), + HOST_HANDLED(SYS_APIBKEYHI_EL1), + HOST_HANDLED(SYS_APDAKEYLO_EL1), + HOST_HANDLED(SYS_APDAKEYHI_EL1), + HOST_HANDLED(SYS_APDBKEYLO_EL1), + HOST_HANDLED(SYS_APDBKEYHI_EL1), + HOST_HANDLED(SYS_APGAKEYLO_EL1), + HOST_HANDLED(SYS_APGAKEYHI_EL1), + + HOST_HANDLED(SYS_AFSR0_EL1), + HOST_HANDLED(SYS_AFSR1_EL1), + HOST_HANDLED(SYS_ESR_EL1), + + HOST_HANDLED(SYS_ERRIDR_EL1), + HOST_HANDLED(SYS_ERRSELR_EL1), + HOST_HANDLED(SYS_ERXFR_EL1), + HOST_HANDLED(SYS_ERXCTLR_EL1), + HOST_HANDLED(SYS_ERXSTATUS_EL1), + HOST_HANDLED(SYS_ERXADDR_EL1), + HOST_HANDLED(SYS_ERXMISC0_EL1), + HOST_HANDLED(SYS_ERXMISC1_EL1), + + HOST_HANDLED(SYS_TFSR_EL1), + HOST_HANDLED(SYS_TFSRE0_EL1), + + HOST_HANDLED(SYS_FAR_EL1), + HOST_HANDLED(SYS_PAR_EL1), + + /* Performance Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_MAIR_EL1), + HOST_HANDLED(SYS_AMAIR_EL1), + + /* Limited Ordering Regions Registers are restricted. */ + + HOST_HANDLED(SYS_VBAR_EL1), + HOST_HANDLED(SYS_DISR_EL1), + + /* GIC CPU Interface registers are restricted. */ + + HOST_HANDLED(SYS_CONTEXTIDR_EL1), + HOST_HANDLED(SYS_TPIDR_EL1), + + HOST_HANDLED(SYS_SCXTNUM_EL1), + + HOST_HANDLED(SYS_CNTKCTL_EL1), + + HOST_HANDLED(SYS_CCSIDR_EL1), + HOST_HANDLED(SYS_CLIDR_EL1), + HOST_HANDLED(SYS_CSSELR_EL1), + HOST_HANDLED(SYS_CTR_EL0), + + /* Performance Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_TPIDR_EL0), + HOST_HANDLED(SYS_TPIDRRO_EL0), + + HOST_HANDLED(SYS_SCXTNUM_EL0), + + /* Activity Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_CNTP_TVAL_EL0), + HOST_HANDLED(SYS_CNTP_CTL_EL0), + HOST_HANDLED(SYS_CNTP_CVAL_EL0), + + /* Performance Monitoring Registers are restricted. */ + + HOST_HANDLED(SYS_DACR32_EL2), + HOST_HANDLED(SYS_IFSR32_EL2), + HOST_HANDLED(SYS_FPEXC32_EL2), +}; + +/* + * Handler for protected VM MSR, MRS or System instruction execution in AArch64. + * + * Return 1 if handled, or 0 if not. + */ +int kvm_handle_pvm_sys64(struct kvm_vcpu *vcpu) +{ + const struct sys_reg_desc *r; + struct sys_reg_params params; + unsigned long esr = kvm_vcpu_get_esr(vcpu); + int Rt = kvm_vcpu_sys_get_rt(vcpu); + + params = esr_sys64_to_params(esr); + params.regval = vcpu_get_reg(vcpu, Rt); + + r = find_reg(¶ms, pvm_sys_reg_descs, ARRAY_SIZE(pvm_sys_reg_descs)); + + /* Undefined access (RESTRICTED). */ + if (r == NULL) { + inject_undef(vcpu); + return 1; + } + + /* Handled by the host (HOST_HANDLED) */ + if (r->access == NULL) + return 0; + + /* Handled by hyp: skip instruction if instructed to do so. */ + if (r->access(vcpu, ¶ms, r)) + __kvm_skip_instr(vcpu); + + vcpu_set_reg(vcpu, Rt, params.regval); + return 1; +} + +/* + * Handler for protected VM restricted exceptions. + * + * Inject an undefined exception into the guest and return 1 to indicate that + * it was handled. + */ +int kvm_handle_pvm_restricted(struct kvm_vcpu *vcpu) +{ + inject_undef(vcpu); + return 1; +} -- 2.32.0.272.g935e593368-goog _______________________________________________ kvmarm mailing list [email protected] https://lists.cs.columbia.edu/mailman/listinfo/kvmarm
